To provide modular control over File Management and Personal Information Management (Contacts and Calendar), can Disroot transform the service "cloud.disroot.org" (Nextcloud) into "fm.disroot.org" (Seafile) and "pim.disroot.org" (Radicale)?

You should probably take this to the xmpp group because that's more active. Migrating lots of users and all their files, contacts, calenders and idk what else would be a huge task. So I guess this is not going to happen anytime soon.

That is not in the scope of disroot as an instance. We have chosen this setup as a ground point to make it easy for people disrooting to change their habits. Such radical change as proposed by you cannot happen as not everyone will agree with "your" way.

However that does not mean we couldn't have a new "node" (instance) with different approach such as the one you suggested. That however requires a lot of work (labor) and finances, which at this moment we simply dont have. That does not mean it's not possible in the future.